Some Benefit Seen for Ovary Removal at Hysterectomy

Action Points

Explain that removing the ovaries at the same time as the uterus made a small risk of subsequent ovarian cancer even smaller without significantly increasing other risks.

Note that the study also found no evidence of increased morbidity or mortality among the women choosing simultaneous bilateral salpingo-oophorectomy (BSO) and hysterectomy.

Point out that the findings of the current study contradict those seen in another large cohort, the Nurses' Health Study, suggesting that the safety of BSO may not yet be finally resolved.

Removing the ovaries at the same time as the uterus made a small risk of subsequent ovarian cancer even smaller without significantly increasing other risks, results of a large observational study showed.

Among more than 25,000 women without a family history of ovarian cancer who had a hysterectomy, those keeping their ovaries were later diagnosed with ovarian cancer at a rate of 0.33%, compared with 0.02% in the women who also had elective bilateral salpingo-oophorectomy (BSO), reported Vanessa L. Jacoby, MD, MAS, of the University of California San Francisco, and colleagues.

The researchers also found no evidence of increased morbidity or mortality among the women choosing simultaneous BSO and hysterectomy, they indicated in the April 25 issue of Archives of Internal Medicine.

Cardiovascular events, hip fracture, and breast cancer were no more common in women undergoing BSO than in those choosing ovarian conservation, the researchers indicated.

But Jacoby and colleagues cautioned against a conclusion that simultaneous BSO is a sensible precaution in women without known ovarian cancer risk who are scheduled for hysterectomy.

"Given the very low rate of ovarian cancer after hysterectomy with ovarian preservation, BSO may provide minimal additional benefit," they wrote.

They also noted that their findings contradicted those seen in another large cohort, the Nurses' Health Study, suggesting that the safety of BSO may not yet be finally resolved.

Jacoby and colleagues indicated that it was already well-known -- not to mention obvious -- that ovary removal in BSO prevents ovarian cancer. But long-term risks associated with the procedure remained largely unknown.

Some smaller studies had found increased rates of cardiovascular disease and increased hip fractures, but others had not, they wrote.

Current guidelines from the American Congress of Obstetricians and Gynecologists recommends BSO for women known to be at risk for ovarian cancer but ovarian preservation in those without such risk.

The new findings came from the Women's Health Initiative Observational Study, which enrolled 25,448 postmenopausal women who had previously had hysterectomies and no family history of ovarian cancer. Slightly more than half (56%) had also undergone BSO along with the hysterectomy.

Mean follow-up after the procedures was 7.6 years.

In a multivariate statistical model, rates of 10 adverse outcomes did not differ significantly between women choosing BSO and those with ovaries left intact.

Those outcomes included all-cause mortality, total coronary heart disease diagnoses, cardiovascular interventions, strokes, total cardiovascular disease, hip fracture, total cancers, and cancers of the breast, bowel, and lung.

The presence or absence of hormone replacement therapy following BSO made no difference in the results.

The only hint of an adverse effect associated with BSO was in invasive cancers affecting women with hysterectomies before age 40. In this group, the hazard ratio was 0.72 for ovarian conservation relative to simultaneous BSO (95% CI 0.51 to 1.02).

Technically, even the rates of ovarian cancer did not differ significantly, but that was because there were only three cases among the 11,194 women undergoing BSO, which was too few for multivariate analysis to be performed, according to Jacoby and colleagues.

The unadjusted rate of ovarian cancer was three per 100,000 person-years of postprocedural exposure with BSO compared with 44 per 100,000 in the women with intact ovaries.

But the findings for the other outcomes were considerably different from those of the Nurses' Health Study, and Jacoby and colleagues conceded that their data were different and perhaps inferior in some ways.

Although most participants in both studies underwent hysterectomy in their 40s, the Women's Health Initiative cohort was older at enrollment by about 12 years (mean age 63 versus 51) and follow-up was shorter.

These differences, Jacoby and colleagues wrote, "may explain some of the variation in our findings."

They also cited some limitations to their data, which included participants' self-report of BSO, the possibility of survivor bias, and potential confounding by unmeasured variables -- although they had data on dozens of sociodemographic and clinical features that were included in their statistical model.

In an accompanying commentary, two researchers at Washington University in St. Louis commented that the dueling findings of the two studies highlight the importance of not basing recommendations on a single study.